200428320 玖、發明說明： ㈠[發明所屬之技術領域] 本發明係關於具有依據電流源供應之電流實施胃％ 2 電流發光兀件的影像顯不裝置’尤其是，關於具有改變連 結於電流源之配線構造之電位的構造之影像顯示_ g。 ㈡[先前技術] 採用本身會發光之有機電場致光（EL)元件的有機EL顯 示裝置，因無需液晶顯示裝置上必要之背光源，故最適# 裝置之薄型化，且因爲視角亦無限制，故期待其能成爲次 世代之顯示裝置而被實用化。 採用有機EL元件之影像顯示裝置的驅動方式上，單純 (被動）矩陣型及主動矩陣型爲大家所熟知。前者之構造雖 然單純，然而，卻有不易實現大型化及高精細化顯示器之 問題。因此，近年來，同時利用例如薄膜電晶體（Thin Film Transistor:薄膜電晶體）之設置於像素內之能動元件來控制 流過像素內部之發光元件的電流之主動矩陣型顯示裝置的 開發十分盛行。 第5圖係傳統技術之主動矩陣方式有機EL顯示裝置的 像素電路。傳統技術之像素電路的構造上，係具有：電流 發光元件之有機EL元件105 ;汲極連結於有機EL元件105 之負側、源極連結於接地，作爲驅動元件之機能的薄膜電 晶體104;連結於薄膜電晶體104之閘極及接地之間的電容 器1 〇3 ;以及汲極連結於薄膜電晶體1 04之閘極、源極連結 於信號線1 0 1、閘極連結於掃描線1 〇 6，作爲開關元件之機 能的薄膜電晶體1 02。其次，有機EL顯示裝置具有供應流 200428320 過有機EL元件105之電流的電流源107，電流源107之構 造上，係經由配線構造1 〇 8和薄膜電晶體1 04電性連結。 在第5圖所示之像素電路，信號線1 0 1會將對應顯示亮 度之電壓經由薄膜電晶體102供應至電容器103。因爲電容 器103係配置於薄膜電晶體104之閘極、源極間，故薄膜 電晶體104之閘極、源極間電壓會等於電容器103蓄積之 電壓，利用此閘極臨界値源極間電壓可在源極、汲極間形 成特定之通道。電流源107會對應實現薄膜電晶體104之 通道的移動度來供應電流，電流會流至和薄膜電晶體1 04 之源極、汲極間及薄膜電晶體1 04爲串聯之有機EL元件 105，有機EL元件105則會以期望之亮度發光（例如，參照 專利文獻1。）。 然而，組合著可補償薄膜電晶體1 04之臨界値電壓變動 的補償電路之影像顯示裝置亦爲大家所熟知。爲了抑制各 顯示像素之驅動元件的IV特性變動，薄膜電晶體1 04之通 道形成區域應採用非晶矽。然而，大家都知道，使用非晶 矽時，在長期使用下，其臨界値電壓會產生變動，因爲從 高品質之影像顯示的觀點而言，最好能實施臨界値電壓變 動之補償。 補償電路有各種構成，而大家所熟知之構造實例之一， 就是配置電壓補償用薄膜電晶體，利用此薄膜電晶體之動 作及配線構造1 08之電位變動的組合來實施電壓補償。配 置此補償電路時，電流源1 07不但具有對有機EL元件1 〇5 供應電流之機能，尙需要執行利用對配線構造1 〇 8供應電 荷來變動配線構造1 0 8之電位的動作。 200428320 [專利文獻1 ] 曰本特開平8-234683號公報（第10頁、第1圖） ㈢[發明內容] 然而，採用有機EL元件之影像顯示裝量，因在影像顯 示時對有機EL元件供應電流之構造而具有各種問題。實際 之影像顯示裝置上，從電流源1 0 7到配置於遠處之顯示像 素的配線構造1 〇 8之物理長度需較大，爲了抑制電阻値隨 著物理長度之增大而增加，必須增加配線構造1 0 8之剖面 積。 另一方面，配線構造1 0 8之剖面積的增加，會導致配線 構造1 08及其他配線構造之重疊面積的增加，例如和掃描 線1 0 6之重疊面積的增加，而增加配線構造1 〇 8之寄生電 容。而寄生電容增加所導致之問題，例如，在影像顯示裝 置組合補償電路之改變配線構造1 0 8之電位的構造時，會 更爲明顯化。 例如’組合補償電路來實施薄膜電晶體1 04之臨界値電 壓變動補償時，動作時需改變配線構造108之電位。爲了 改變電位而需對寄生電容供應電荷，故配線構造1 〇8之寄 生電容增加時，電位變動所需要之時間會對應其增加量而 增加。 電位變動所需要之時間增加，意味代表電壓補償上所需 要之時間亦會增加，結果，會對影像顯示裝置之高精細化 或大畫面化上造成限制。亦即，臨界値電壓變動之補償除 了必須對設置於各像素之全部驅動元件來實施以外，以對 全部驅動元件實施電壓補償爲目的之容許時間亦受到特定 200428320 値之限制。因此，爲實現影像顯示裝置之高精細化或大畫 面化而需要增加像素數，故必須減少對各個驅動元件之電 壓補償所需要的時間。 又，實施配線構造1 0 8之電位變動時，電流源1 07之電 力消耗亦是問題。因爲補償電路一般係針對各圖框執行動 作，而電流源1 07爲了改變配線構造108之電位，即必須 對不同於各圖框之發光步驟的配線構造1 08供應電流。其 次，因爲配線構造1 08上會存在某種程度之電阻及寄生電 容等，而無法避免電流源1 07隨著配線構造1 0 8之電位變 動而產生特定量之電力消耗。此電力消耗若很輕微則不會 形成問題，然而，實際上，除了需要無法忽視之程度的消 耗電力以外，電流源1 07產生之熱對影像顯示裝置及電流 源107本身所造成的不良影響亦應考量。 有鑑於上述傳統技術之問題，本發明之目的即在提供一 種影像顯示裝置，具有改變連結於電流源上之配線構造的 電位的構成，可在避免電流源之驅動上的負荷下，實施配 線構造之電位變動。 爲了達成上述目的，申請專利範圍第1項之影像顯示裝 置的特徵係具有：可發出對應流入之電流値的亮度之光的 電流發光元件；和該電流發光元件電性連結之配線構造； 控制該配線構造之電位的電位控制裝置；以及在前述電流 發光元件發光後改變前述配線構造之電位時，控制前述電 位控制裝置及前述配線構造間之導電度的電位變動補助裝 置〇 依據此申請專利範圍第1項之發明，因爲電位變動補助 200428320 裝置會補助配線構造之電位變動，故在改變配線構造之電 位時可減輕電位控制裝置之負擔。 又，申請專利範圍第2項之影像顯示裝置的特徵，係上 述發明之前述電位變動補助裝置在前述電流發光元件發光 後，會使前述電位控制裝置及前述配線構造間形成電性絕 緣，前述配線構造則會依據前述通過電流發光元件之電流 改變電位。 依據此申請專利範圍第2項之發明，改變配線構造之電 位時係利用通過電流發光元件之電流，故無需另行設置新 驅動電路等即可實施電位變動。 又，申請專利範圍第3項之影像顯示裝置的特徵，係上 述發明之前述電位變動補助裝置在使前述電位控制裝置及 前述配線構造間形成電性絕緣並經過特定時間後，會再度 使前述電位控制裝置及前述配線構造形成電性連結，前述 電位控制裝置在再度和前述配線構造形成電性連結後，會 實施前述配線構造之電位的微調。 又，申請專利範圍第4項之影像顯示裝置的特徵，上述 發明更具有··依據施加電壓控制流入前述電流發光元件之 電流値的驅動元件；供應施加於該驅動元件上之電壓的信 號線；控制該信號線之電壓供應時序的開關元件；以及控 制該開關元件之驅動狀態的掃描線。 又，申請專利範圍第5項之影像顯示裝置的特徵，係上 述發明之前述電位控制裝置在前述電流發光元件發光時會 控制前述配線構造之電位，對前述電流發光元件之陽極及 陰極間供應特定電壓。 200428320 又，申請專利範圍第6項之影像顯示裝置的特徵，係上 @發明之前述電流發光元件的陰極側和前述配線構造電性 連結，而陽極側則連結於接地線，前述電位控制裝置在前 述電流發光元件發光時會控制前述配線構造之電位，使前 述配線構造處於負電位。 又，申請專利範圍第7項之影像顯示裝置的特徵，係上 述發明之前述電流發光元件含有有機EL元件。 ㈣[實施方式] 以下，參照圖面說明本發明之實施形態的影像顯示裝 置。又，圖面係模式圖，故請注意其和現實之物會有不同 之處。又，圖面與圖面間，當然亦會有尺寸關係比率不同 的部分。 本實施形態之影像顯示裝置具有配線構造，前述配線構 造係電性連結於具有電流發光元件之機能的有機EL元件 上。其次，實施此配線構造之電位變動時，配線構造會和 其他部份絕緣，並在浮動狀態下流入流過有機EL元件之電 流’而爲利用此電流之流入來改變配線構造之電位的構 造。 第1圖係本實施形態之影像顯示裝置之構成的電路 圖。本實施形態之影像顯示裝置如第1圖所示，具有複數 配置之像素電路1、對像素電路1供應特定之電位的掃描 線2及信號線3、對配置於像素電路1內之電流發光元件供 應電流之配線構造4、以及控制配線構造4之電位的電位 控制部5。其次，本實施形態之影像顯示裝置，具有配置 於配線構造4及電位控制部5間且可控制配線構造4及電 -10- 200428320 位控制部5間之電性連結狀態的開關部6、電性連結於掃 描線2之掃描線驅動電路7、以及連結於信號線3之信號線 驅動電路8。 像素電路1係對應顯示像素複數配置成矩陣狀，各個像 素電路1會分別顯示特定亮度之光，而使影像顯示裝置全 體實施影像顯示。具體而言，像素電路1具有：閘極連結 著掃描線2、另一方之源極/汲極上則連結著信號線3，且 具有開關元件之機能的薄膜電晶體9 ;及具有和薄膜電晶 體9之另一方之源極/汲極相連結之閘極，且具有驅動元 件之機能的薄膜電晶體10。又，像素電路1具有：陽極側（陰 極側）連結於薄膜電晶體1 0之一方源極/汲極且陰極側（陽 極側）連結於接地，作爲電流發光元件之機能的有機EL元 件1 2 ;及配置於薄膜電晶體1 0之閘極、源極間，保存信號 線3供應之電壓的電容器1 1。 有機EL元件1 2係具有以對應於注入之電流値的亮度實 施發光之電流發光元件的機能者，具體之構造上，係依序 實施陽極層、發光層、及陰極層之積層。發光層係以從陰 極層側注入之電子、及從陽極層側注入之正電洞的發光再 結合爲目的者，具體而言，係酞花青、三鋁錯合物、苯並 喹啉錯合物、鈹錯合物等有機系材料所形成，必要時，可 具有特定雜質之合點化構造。又，有機EL元件12之構造 上’亦可針對發光層在陽極側設置正電洞輸送層，並針對 發光層在陰極側設置電子輸送層。 掃描線2係以控制具有開關元件之機能的薄膜電晶體9 之驅動狀態爲目的者。具體而言，掃描線2係連結於掃描 -11- 200428320 線驅動電路7，掃描線驅動電路7則具有施加特定電壓之 機能，可使配合電壓寫入時序選取之薄膜電晶體9處於導 通狀態。 信號線3係以經由具有開關元件之機能的薄膜電晶體9 對電容器1 1供應寫入電壓爲目的者。具體而言，信號線3 係連結於信號線驅動電路8，信號線驅動電路8則會對電 容器1 1供應電壓，前述電壓係對應於依據外部輸入之影像 信號而決定之有機EL元件12的發光亮度。 配線構造4係以連結薄膜電晶體1 〇之另一方之源極/ 汲極及電位控制部5之間爲目的者。具體構造上，係連結 於薄膜電晶體1 0之另一方之源極/汲極，而對電位控制部 5則以開關部6連結。又，本實施形態亦如第1圖所示，其 構造上，係連結於屬於同一列之像素電路1所具有之薄膜 電晶體1 0上。 開關部6係以控制電位控制部5及配線構造4間之電性 導通爲目的者。具體而言，開關部6之構造上，係由例如 薄膜電晶體所形成，利用控制施加於閘極、源極間之電壓 來控制導通狀態或斷開狀態，使配線構造4及電位控制部5 處於電性連結或絕緣。本實施形態之開關部6因具有電位 變動補助裝置之機能，故可減輕改變配線構造4之電位時 之電位控制部5的負擔。 其次，針對本實施形態之影像顯示裝置的動作進行說 明。本實施形態之影像顯示裝置因係依序實施使有機EL 元件1 2以期望之亮度實施發光之發光步驟、及改變配線構 造4之電位的電位變動步驟，故以下首先針對發光步驟進 -12- 200428320 行簡單說明，其後再對電位變動步驟進行說明。 第2圖（a)係說明發光步驟之模式圖。發光步驟時，會 選取特定之像素電路1並由掃描線2對配置於像素電路1 內之薄膜電晶體9的閘極供應特定電壓，使薄膜電晶體9 處於導通狀態。另一方面，信號線3會利用信號線驅動電 路8，對配置於像素電路1內之有機EL元件1 2供應對應 欲顯示之亮度的電壓，此電壓會經由導通狀態之薄膜電晶 體9寫入至電容器11。如前面所述，因爲電容器丨丨係配置 於薄膜電晶體1 0之閘極、源極間，寫入至電容器u之電 壓會直接成爲薄膜電晶體1 0之閘極、源極間電壓。 另一方面，如第2圖（a)所示，發光步驟時，開關部6 會維持於導通狀態，而電位控制部5及配線構造4亦會維 持於電性連結之狀態。又，電位控制部5在發光步驟時會 實施控制，使配線構造4之電位値遠小於有機£ l元件12 之陽極側的電位値。本實施形態時，除了有機E L元件1 2 之陽極側接地以外，配線構造4之電位亦維持於負電位_ VDD(VDD>0) 〇 因爲配線構造4維持於負電位，在薄膜電晶體1 〇維持 於導通狀態之期間，會依順向對有機E L元件1 2施加電壓。 因此，電流會依第2圖（a)所示之箭頭方向流過有機£ L元 件1 2，亦即順向流過電流，且薄膜電晶體1 〇會控制流過之 電流値，而使有機EL元件1 2以特定亮度發光。 又’如上面所述之發光步驟時，因爲開關部6係維持於 導通狀態’故配線構造4之電位亦會因電位控制部5而維 持於特定値’結果，一方之電極連結於配線構造之電容器 -13- 200428320 11的極板間電壓亦會大致維持於特定値。因此，薄膜電晶 體1 0之閘極、源極間電壓亦會大致維持於特定値，而在發 先步驟期間會有特定電流流過有機E L元件1 2，而實施特 疋壳度之發光。此發光步驟係依序對複數配置之像素電路1 實施，結果，各像素電路之有機EL元件1 2會以期望之亮 度貫施發光’而顯不特定圖案之影像。 其次’針對改變配線構造4之電位的電位變動步驟進行 說明。第2圖（b)係電位變動步驟之模式圖。首先，開關部 6會處於斷開狀態，配線構造4及電位控制部5間爲電性絕 緣，配線構造4則處於浮動狀態。 因爲電容器11會殘留發光步驟時寫入之電壓，會對薄 膜電晶體1 0施加特定之閘極、源極間電壓，並維持導通狀 態。因此，和發光步驟相同，電流會以順向流過有機EL 元件1 2，此電流會通過薄膜電晶體1 0並流入配線構造4。 第3圖係各個像素電路1之電位變動步驟開始後通過薄 膜電晶體1 〇並流入配線構造4之電流値的時間變動圖。 又，第3圖之圖表中，發光步驟時流過有機EL元件12之 電流値爲I。。如第3圖所示，在發光步驟結束並進入電位 變動步驟後，亦會有特定量之電流通過有機EL元件1 2並 流入配線構造4。 又，利用開關部6處於斷開狀態，使配線構造4處於浮 動狀態，並使配線構造4之電位V因爲流入之電流而從發 光步驟時之·VDD値逐漸增加。此時，如第1圖及第2圖所 示，配線構造4之構造上’因係電性連結於屬於同一列之 複數像素電路1所具有之薄膜電晶體1 〇上’屬於同一列之. -14- 200428320 複數像素電路1會對配線構造4供應電流。 又，實際上，薄膜電晶體1 0之閘極、源極間電壓降至 臨界値電壓以下之時點爲止，電流會流入配線構造4，配 線構造4之電位直到該時點爲止會持續上昇。然而，因爲 流入之電流値會逐漸減少，本實施形態在配線構造之電位 成爲- (1/2)VDD之時點，開關部6會再度處於導通狀態，而 切換成利用電位控制部5實施電位控制。 開關部6導通後，通過有機EL元件1 2及薄膜電晶體1 0 之電流、及依據電位控制部5供應之電流的配線構造4之 φ 電位會同時改變成期望之値。以上，即完成電位變動步驟。 本實施形態之影像顯示裝置的構成上，針對具有驅動元 件之機能之薄膜電晶體1 0的源極，改變電性連結之配線構 造4的電位時，係利用通過有機EL元件1 2流入配線構造4 之電流所產生之作用。針對此構成所具有之優點進行說 明。 如前面說明所示，因爲配線構造4之構造上，係電性連 結於屬於同一列之像素電路1，故配線構造4之構造上， | 係在顯示畫面之 向上延伸，故物理長度極大。因此，配 線構造4和信號線3等其他配線構造不得不形成立體交 叉，而這些交叉之配線構造間會產生某種程度之寄生電 容。又，其構成上，係和配置於各像素電路1內之電容器 11爲電性連結，故會存在電容器11所造成之電容。因爲以 上諸點，配線構造4分別具有5 000 pF程度之寄生電容，因 爲此寄生電容之存在，欲改變電位則需對配線構造4供應 特定量之電荷。 -15- 200428320 因此，以電位變動爲目的而只由電位控制部5對配線構 造4供應電荷之構成時，不但需要較長之時間，亦會因爲 電荷供應而增加電位控制部5之負擔，而有電位控制部5 發熱等問題。相對於此，本實施形態時，以電位變動爲目 的而供應之電荷的一部份，係利用通過有機EL元件1 2之 電流來供應，故可減少電位控制部5供應之電荷量。具體 而言，例如，必要之電荷的5 0 %係由通過薄膜電晶體1 0之 電流來供應時，可減少5 0 %電位控制部5在電位變動步驟 時之消耗電力，其發熱量亦比傳統降低5 0 %。 第4圖係和第3圖相同之條件下，電位變動步驟時之通 過薄膜電晶體1 〇流入之電流所造成之配線構造4電位之時 間變動的數値計算結果圖。如第4圖所示，電位變動步驟 剛開始時，配線構造4之電位會急速上昇，電位變動步驟 開始後之0.1ms間會上昇達50 %程度。電位變動步驟可實 現使用之配線構造4的電位爲例如OV時，則可在0.1ms 間供應50%之必要電荷。 又，利用通過薄膜電晶體1 0之電流而可在短時間內實 施電位變動，具有可抑制顯示影像之品質降低的優點。亦 即，因爲流入配線構造4之電流只有通過有機EL元件1 2 電流，電流流入配線構造4之期間，有機EL元件12會以 特定亮度發光。另一方面，採用有機EL元件1 2之影像顯 示裝置時，尤其爲了提高動畫顯示時之辨識性，顯示不同 影像之期間最好實施特定期間之黑色顯示。具體而言，例 如，相當於1圖框容許之時間（約1 6 m s)的一半之8 m s的期 間，使有機EL元件1 2以期望之亮度發光實施實際之影像 -16 - 200428320 顯示，其餘之8ms的期間，則最好停止有機EL元件12之 發光而爲黑色顯示。 因此，若在發光步驟以外實施之電位變動步驟時，若有 機EL元件1 2之發光時間較長，則表示黑色顯示之時間會 減少，故影像品質會降低。相對於此，本實施形態時，電 位變動步驟時之有機EL元件1 2的發光時間，在第4圖之 實例中，只需0.1ms程度之短時間即會停止，故實質上對 黑色顯示時間之影響係可忽視，而可維持高品質之影像顯 示特性。 又，亦如第3圖所示，電位變動步驟時，流過薄膜電晶 體1 0之電流値，亦即，流過有機EL元件1 2之電流値和發 光步驟並非完全一致，而會隨著時間之經過而減少。因此， 電位變動步驟時之有機EL元件1 2的亮度和發光步驟時並 不相同，長時間發光時，畫面上會顯示和欲顯示之影像不 同的影像。然而，本實施形態之影像顯示裝置如第4圖所 示，因爲可將電位變動步驟時之有機EL元件1 2的發光時 間抑制於0· lms程度，使用者幾乎無法辨識此發光狀態。 因此，本實施形態之影像顯示裝置時，亦可抑制此觀點下 之影像品質降低。 又，本實施形態之影像顯示裝置之構造，因爲在電位變 動步驟時係經由有機EL元件1 2對配線構造4供應電流， 故具有無需另行增設電流源等之優點。亦即，發光步驟結 束之時點，寫入電容器Π之電壓會維持和發光步驟大致相 同的値，且處於對有機EL元件1 2施加順向電壓之狀態。 因此，進入電位變動步驟之時點，亦如第3圖所示而和發 •17- 200428320 光步驟相同’維持電流流過薄膜電晶體1 〇之源極、汲極間 的狀悲。因此’電位變動步驟時’無需以經由薄膜電晶體 1 0對配線構造4供應電流爲目的之特別電路等，而可直接 採用傳統之構造。 又，本實施形態之影像顯示裝置時，並非只以經由薄膜 電晶體1 0流入配線構造4之電流來控制配線構造4之電 位，而係在進入電位變動步驟並經過特定時間後再度使開 關部6處於導通狀態而利用電位控制部5來控制配線構造4 之電位。故以下係針對配線構造4之電位變動時倂用電位 控制部5之作用的優點來進行說明。 如以上所述，經由薄膜電晶體1 0流入配線構造4之電 流的値，係由薄膜電晶體1 0之閘極、源極間電壓來決定。 此時，因爲薄膜電晶體10之源極及電容器11之一方電極 係電性連結於配線構造4，故薄膜電晶體1 0之閘極、源極 間電壓會隨著配線構造4之電位上昇而降低，流過源極、 汲極間之電流的値亦會減少。因此，若只以通過薄膜電晶 體1 0之電流來實施配線構造4之電位變動，則可能有因爲 電流値減少而無法使配線構造4達到期望之電位、或到達 期望之電位需要較長時間之問題。 又，因爲薄膜電晶體1 0之閘極、源極間電壓的値係對 應發光步驟時之有機EL元件1 2的亮度而決定’所以各像 素電路1之各圖框會不同，即使爲同一像素電路’各圖框 亦會不同。因此，各特定像素電路或各圖框在電位變動步 驟開始時流入配線構造4之電流會不同，而依據流入電流 之配線構造4的電位變動値亦會不同。因此’只以通過薄 -18- 200428320 1 ! I ϊ 膜電晶體1 0之電流將配線構造4之電位改變成期望之値有 其困難，故必須另行設置以調整通過薄膜電晶體1 0之電流 値的差異等爲目的之裝置。 因此，本實施形態之影像顯示裝置的構造上，係保留電 位控制部5，同時實施利用經由有機EL元件1 2流入之電 流的電位變動、及利用電位控制部5之電位變動。利用倂 用兩者之構造，可補償流過有機EL元件1 2之電流的差異 等並實施配線構造4之電位變動。又，本實施形態之影像 顯示裝置雖然保留電位控制部5，然而，如前面所述，和 φ 傳統相比，可以減輕驅動負擔且可降低發熱量。 以上係利用實施形態針對本發明之影像顯示裝置進行 說明，然而，本發明並未受實施形態之限制，只要爲該業 者即可依據實施形態聯想到各種實施例及變形例等。例 如，構成影像顯示裝置之像素電路的構造並未限定爲如第1 圖所示者，例如，亦可如應用例之第5圖所示之構造，將 有機EL元件1 2之陽極連結於薄膜電晶體1 0之源極。又， 配線構造4之配置位置並未限定爲依電流流動方向而爲像 φ 素電路1之下游位置，其構造上，亦可例如配置於像素電 路1之上游。 又，實施形態中之電流發光元件係以有機EL元件爲 例，然而，亦可採用無機EL元件等。又，電流發光元件不 必和發光二極體爲電性等效，其構造上，亦可以爲電流朝 順向及逆向之其中任一方流過時皆可發光。採用此種電流 發光元件時，因爲電流不但會通過薄膜電晶體1 〇流入配線 構造4，電流亦會從配線構造4流出至薄膜電晶體1 0側， -19- 200428320 故具有增加電位變動範圍之優點。 又，實施形態之開關部6之構造上’係使配線構造4及 電位控制部5間成爲絕緣，然而，其構造上，亦可爲改變 兩者間之電阻値。即使未完全絕緣，而只需使電流不易從 配線構造4流入電位控制部5，配線構造4上即可畜積特定 比率之電荷，利用此電荷之蓄積即可改變配線構造4之電 位。 如以上說明所示，依據此發明，其構成上，係以電位變 動補助裝置補償配線構造之電位變動，可減輕改變配線構 φ 造之電位時之電位控制裝置的負擔，故具有降低電位控制 裝置之消耗電力、及電位控制裝置產生之熱的效果。 又，依據此發明，其構成上，改變配線構造之電位時係 利用通過電流發光元件之電流，故具有無需另行設置新驅 動電路等來實施電位變動之效果。 ㈤[圖式簡單說明] 第1圖係實施形態之影像顯示裝置的構成模式圖。 第2 (a )圖係實施形態之影像顯示裝置的動作模式圖的發 0 光步驟，第2(b)圖係電位變動步驟。 第3圖係通過有機EL元件流入配線構造之電流値的時間 變化圖。 第4圖係配線構造之電位的時間變化圖。 第5圖係傳統技術之影像顯示裝置的構成電路圖。 [元件符號之說明] 1…像素電路 2…掃描線 -20- 200428320 3…信號 4…配線 5…電位 6、13··· 7…掃描 8…信號 9、10··· 1 1…電3 12…有ί 1 0 1…信 1 0 2…薄 103…電 1 〇 4…薄 105…有 1 0 6…掃 107…電 1 0 8…配 線 步驟 控制部 開關部 線驅動電路 線驅動電路 薄膜電晶體 ?器 I EL元件 號線 膜電晶體 容器 膜電晶體 機EL元件 描線 流源 線構造200428320 发明, Description of the invention: ㈠ [Technical field to which the invention belongs] The present invention relates to an image display device having an electric current emitting element based on a current supplied by a current source. In particular, it relates to a device having a change connected to a current source. The image of the potential structure of the wiring structure shows _ g.先前 [Previous technology] An organic EL display device using an organic electroluminescence (EL) element that emits light by itself is the most suitable for thinning the device because it does not require the necessary backlight source on the liquid crystal display device, and because the viewing angle is also unlimited, Therefore, it is expected to be put into practical use as a next-generation display device. In the driving method of an image display device using an organic EL element, a simple (passive) matrix type and an active matrix type are well known. Although the former structure is simple, it has a problem that it is not easy to realize a large-scale and high-definition display. Therefore, in recent years, development of an active matrix display device that simultaneously uses, for example, a thin film transistor (Thin Film Transistor) active element provided in a pixel to control a current flowing through a light emitting element inside the pixel. FIG. 5 is a pixel circuit of an active matrix organic EL display device of the conventional technology. The structure of the pixel circuit of the conventional technology includes: an organic EL element 105 of a current-emitting element; a thin-film transistor 104 having a drain connected to the negative side of the organic EL element 105 and a source connected to ground as a driving element; A capacitor 1 〇3 connected between the gate and the ground of the thin film transistor 104; and a drain connected to the gate of the thin film transistor 104, a source connected to the signal line 1 0, and a gate connected to the scanning line 1 〇6. Thin film transistor 102 as a function of a switching element. Next, the organic EL display device has a current source 107 that supplies a current of 200428320 through the organic EL element 105. The structure of the current source 107 is electrically connected to the thin film transistor 104 through a wiring structure 108. In the pixel circuit shown in FIG. 5, the signal line 101 supplies the voltage corresponding to the display brightness to the capacitor 103 via the thin film transistor 102. Because the capacitor 103 is disposed between the gate and the source of the thin film transistor 104, the voltage between the gate and the source of the thin film transistor 104 will be equal to the voltage accumulated by the capacitor 103. Using this gate critical 値 source voltage can A specific channel is formed between the source and the drain. The current source 107 will supply current corresponding to the movement of the channel of the thin film transistor 104, and the current will flow to the source, drain and thin film transistor 104 of the thin film transistor 104 as an organic EL element 105 connected in series. The organic EL element 105 emits light at a desired brightness (for example, refer to Patent Document 1). However, an image display device incorporating a compensation circuit capable of compensating the critical 値 voltage variation of the thin film transistor 104 is also well known. In order to suppress the variation of the IV characteristics of the driving elements of each display pixel, the channel formation region of the thin film transistor 104 should be made of amorphous silicon. However, as everyone knows, when using amorphous silicon, its critical threshold voltage will change over a long period of time, because from the standpoint of high-quality image display, it is best to compensate for critical threshold voltage changes. The compensation circuit has various structures, and one of the well-known structural examples is to configure a thin film transistor for voltage compensation, and use the combination of the operation of this thin film transistor and the potential variation of the wiring structure to implement voltage compensation. When the compensation circuit is configured, the current source 107 not only has a function of supplying current to the organic EL element 105, but also needs to perform an operation of changing the potential of the wiring structure 108 by supplying a load to the wiring structure 108. 200428320 [Patent Document 1] Japanese Unexamined Patent Publication No. 8-234683 (p. 10, Fig. 1) 发明 [Disclosure of the Invention] However, an organic EL element is used for an image display capacity because the organic EL element is displayed during image display. The structure of the current supply has various problems. On an actual image display device, the physical length from the current source 107 to the wiring structure 1 0 of the display pixels arranged at a distance needs to be large. In order to suppress the resistance, it must be increased as the physical length increases. The cross-sectional area of the wiring structure 108. On the other hand, an increase in the cross-sectional area of the wiring structure 108 will lead to an increase in the overlapping area of the wiring structure 108 and other wiring structures, such as an increase in the overlapping area with the scanning line 106, and an increase in the wiring structure 1.0. 8 parasitic capacitance. Problems caused by an increase in parasitic capacitance, for example, become more apparent when the structure of the wiring structure of the image display device is changed to a potential of 108. For example, when 'combination compensation circuit is used to compensate the critical voltage fluctuation of the thin film transistor 104, the potential of the wiring structure 108 needs to be changed during operation. In order to change the potential, it is necessary to supply a charge to the parasitic capacitance. Therefore, when the parasitic capacitance of the wiring structure 108 is increased, the time required for the potential variation will increase according to the increase amount. The increase in the time required for the potential change means that the time required to represent the voltage compensation will also increase. As a result, it will limit the high definition or large screen of the image display device. That is, in addition to the compensation of the critical threshold voltage, in addition to the necessity to implement all the driving elements provided in each pixel, the allowable time for the purpose of performing voltage compensation on all the driving elements is also limited by a specific 200428320 threshold. Therefore, it is necessary to increase the number of pixels in order to achieve high definition or large screen size of the image display device, so it is necessary to reduce the time required for voltage compensation of each driving element. In addition, when the potential variation of the wiring structure 108 is implemented, the power consumption of the current source 107 is also a problem. Because the compensation circuit generally performs operations for each frame, and in order to change the potential of the wiring structure 108, the current source 107 must supply current to the wiring structure 108 that is different from the light emitting step of each frame. Secondly, because a certain degree of resistance, parasitic capacitance, etc. may exist on the wiring structure 108, it is impossible to avoid a certain amount of power consumption for the current source 107 as the potential of the wiring structure 108 changes. This power consumption will not cause a problem if it is very small. However, in addition to the power consumption that cannot be ignored, the heat generated by the current source 107 also adversely affects the image display device and the current source 107 itself. Should be considered. In view of the above-mentioned problems of the conventional technology, an object of the present invention is to provide an image display device having a configuration that changes the potential of a wiring structure connected to a current source, and can implement the wiring structure while avoiding a load on the driving of the current source. Potential changes. In order to achieve the above object, the feature of the image display device of the first patent application scope is that it has a current light emitting element that can emit light of brightness corresponding to the current flowing into it; a wiring structure that is electrically connected to the current light emitting element; A potential control device for the potential of the wiring structure; and a potential fluctuation assisting device for controlling the electrical conductivity between the potential control device and the wiring structure when the potential of the wiring structure is changed after the current light-emitting element emits light. In the invention of item 1, since the potential fluctuation subsidy 200428320 device subsidizes the potential variation of the wiring structure, the burden of the potential control device can be reduced when the potential of the wiring structure is changed. In addition, the feature of the image display device in the second scope of the patent application is that the potential fluctuation assisting device of the above invention, after the current light emitting element emits light, electrically isolates the potential control device and the wiring structure, and the wiring The structure changes the potential according to the current passing through the current light-emitting element. According to the invention in item 2 of the scope of this application, when the potential of the wiring structure is changed, the current passing through the light-emitting element is used. Therefore, it is not necessary to install a new driving circuit or the like to implement the potential change. In addition, the feature of the image display device according to item 3 of the patent application is that the potential fluctuation assisting device of the above invention makes the potential again after the electrical insulation between the potential control device and the wiring structure has elapsed for a specific time. The control device and the wiring structure form an electrical connection. After the potential control device forms an electrical connection with the wiring structure again, the potential of the wiring structure is fine-tuned. In addition, the feature of the image display device of the fourth patent application range is that the above invention has a driving element that controls the current 値 that flows into the current light emitting element according to the applied voltage; a signal line that supplies the voltage applied to the driving element; A switching element that controls the timing of voltage supply of the signal line; and a scanning line that controls the driving state of the switching element. In addition, the feature of the image display device in the fifth item of the patent application is that the potential control device of the above invention controls the potential of the wiring structure when the current light-emitting element emits light, and supplies specific information between the anode and cathode of the current light-emitting element. Voltage. 200428320 In addition, the feature of the image display device in the sixth item of the patent application is that the cathode side of the aforementioned current light emitting element and the wiring structure of the invention are electrically connected, and the anode side is connected to the ground wire. The potential control device is When the current light emitting element emits light, the potential of the wiring structure is controlled so that the wiring structure is at a negative potential. The image display device according to claim 7 is characterized in that the current-emitting element of the invention includes an organic EL element. [Embodiment] Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the drawings. Also, the drawing is a pattern diagram, so please note that it is different from the real thing. In addition, of course, there are also parts with different dimensional relationship ratios between the drawing surface and the drawing surface. The image display device of this embodiment has a wiring structure, and the wiring structure is electrically connected to an organic EL element having a function of a current emitting element. Next, when the potential variation of this wiring structure is implemented, the wiring structure is insulated from other parts and flows in a current flowing through the organic EL element in a floating state ', so as to change the potential structure of the wiring structure by using this current inflow. Fig. 1 is a circuit diagram showing the structure of an image display device of this embodiment. As shown in FIG. 1, the image display device of this embodiment includes a plurality of pixel circuits 1, a scanning line 2 and a signal line 3 that supply a specific potential to the pixel circuit 1, and a current light-emitting element disposed in the pixel circuit 1. A wiring structure 4 that supplies current, and a potential control unit 5 that controls the potential of the wiring structure 4. Next, the image display device of this embodiment includes a switch section 6 and a switch section 6 which are arranged between the wiring structure 4 and the potential control section 5 and can control the electrical connection state between the wiring structure 4 and the electric-10-200428320 bit control section 5. The scanning line driving circuit 7 is connected to the scanning line 2 and the signal line driving circuit 8 is connected to the signal line 3. The pixel circuit 1 is arranged in a matrix corresponding to a plurality of display pixels, and each pixel circuit 1 displays light of a specific brightness, so that the image display device performs image display as a whole. Specifically, the pixel circuit 1 includes a thin film transistor 9 having a gate electrode connected to the scanning line 2 and a signal line 3 connected to the other source / drain electrode, and having a function of a switching element; and a thin film transistor having a thin film transistor. The thin-film transistor 10 is a gate connected to the source / drain of the other side and has the function of a driving element. The pixel circuit 1 includes an organic EL element 1 2 having an anode side (cathode side) connected to one of the thin film transistors 10 as a source / drain and a cathode side (anode side) connected to ground. ; And a capacitor 11 arranged between the gate and the source of the thin film transistor 10 and storing the voltage supplied by the signal line 3. The organic EL element 12 is a function of a current-emitting element that emits light at a brightness corresponding to the injected current 値. Specifically, the organic EL element 12 is a laminated structure of an anode layer, a light-emitting layer, and a cathode layer in this order. The light-emitting layer is for the purpose of recombining the electrons injected from the cathode layer side and the positive holes injected from the anode layer side. Specifically, the light-emitting layer is phthalocyanine, trialuminum complex, benzoquinoline, etc. It can be formed from organic materials such as complexes and beryllium complexes, and if necessary, it can have a combined structure of specific impurities. Further, in the structure of the organic EL element 12, a positive hole transport layer may be provided on the anode side for the light emitting layer, and an electron transport layer may be provided on the cathode side for the light emitting layer. The scanning line 2 is for the purpose of controlling the driving state of the thin film transistor 9 having a function of a switching element. Specifically, the scanning line 2 is connected to the scanning -11-200428320 line driving circuit 7, and the scanning line driving circuit 7 has a function of applying a specific voltage, so that the thin film transistor 9 selected in accordance with the writing timing of the voltage can be turned on. The signal line 3 is for the purpose of supplying a write voltage to the capacitor 11 via a thin film transistor 9 having a function of a switching element. Specifically, the signal line 3 is connected to the signal line driving circuit 8. The signal line driving circuit 8 supplies a voltage to the capacitor 11. The foregoing voltage corresponds to the light emission of the organic EL element 12 determined according to an externally input image signal. brightness. The wiring structure 4 is for the purpose of connecting between the other source / drain of the thin film transistor 10 and the potential control unit 5. Specifically, it is connected to the other source / drain of the thin film transistor 10, and the potential control section 5 is connected to the switch section 6. The present embodiment is also shown in Fig. 1. In terms of its structure, it is connected to the thin film transistors 10 included in the pixel circuits 1 belonging to the same row. The switching unit 6 is for the purpose of controlling electrical conduction between the potential control unit 5 and the wiring structure 4. Specifically, the switch section 6 is formed of, for example, a thin film transistor, and controls the on-state or off-state by controlling the voltage applied between the gate and the source, so that the wiring structure 4 and the potential control section 5 Being electrically connected or insulated. Since the switch section 6 of this embodiment has the function of a potential fluctuation assisting device, the burden on the potential control section 5 when the potential of the wiring structure 4 is changed can be reduced. Next, the operation of the video display device of this embodiment will be described. The image display device of this embodiment sequentially implements a light-emitting step that causes the organic EL element 12 to emit light at a desired brightness and a potential change step that changes the potential of the wiring structure 4. Therefore, the following first advances the light-emitting step to -12- The 200428320 line briefly explains the potential fluctuation steps. Fig. 2 (a) is a schematic diagram illustrating a light emitting step. During the light emitting step, a specific pixel circuit 1 is selected and a specific voltage is supplied to the gate of the thin film transistor 9 disposed in the pixel circuit 1 by the scanning line 2 so that the thin film transistor 9 is in an on state. On the other hand, the signal line 3 uses the signal line driving circuit 8 to supply the organic EL element 12 arranged in the pixel circuit 1 with a voltage corresponding to the brightness to be displayed. This voltage is written by the thin-film transistor 9 in the on state. To the capacitor 11. As mentioned above, because the capacitor is placed between the gate and source of the thin film transistor 10, the voltage written to the capacitor u will directly become the voltage between the gate and source of the thin film transistor 10. On the other hand, as shown in Fig. 2 (a), during the light-emitting step, the switch section 6 is maintained in the on state, and the potential control section 5 and the wiring structure 4 are also maintained in the electrically connected state. In addition, the potential control unit 5 performs control during the light emitting step so that the potential 配线 of the wiring structure 4 is much smaller than the potential 阳极 of the anode side of the organic element 12. In this embodiment, in addition to the anode side of the organic EL element 12 being grounded, the potential of the wiring structure 4 is also maintained at a negative potential_VDD (VDD> 0). Because the wiring structure 4 is maintained at a negative potential, the thin film transistor 1 is maintained at a negative potential. While being maintained in the on state, a voltage is applied to the organic EL element 12 in sequence. Therefore, the current flows through the organic element in the direction of the arrow shown in Fig. 2 (a). The L element 12 is a current flowing in the forward direction, and the thin-film transistor 1 0 controls the current flowing through the element 使, thereby making the organic The EL element 12 emits light at a specific brightness. Also, 'the light emitting step as described above, because the switch section 6 is maintained in an on state', the potential of the wiring structure 4 is also maintained at a specific level by the potential control section 5, and as a result, one electrode is connected to the The voltage between the plates of capacitor-13-200428320 11 will also be maintained at a certain level. Therefore, the voltage between the gate and the source of the thin-film electric crystal 10 will also be maintained at a certain level, and a specific current will flow through the organic EL element 12 during the initial step, and the light emitting at a specific level will be implemented. This light emitting step is sequentially performed on a plurality of pixel circuits 1 arranged in a sequence. As a result, the organic EL elements 12 of each pixel circuit will continuously emit light at a desired brightness, and an image with a specific pattern will not be displayed. Next, a step of changing the potential of the potential of the wiring structure 4 will be described. Figure 2 (b) is a schematic diagram of the potential fluctuation steps. First, the switch section 6 is in an off state, the wiring structure 4 and the potential control section 5 are electrically insulated, and the wiring structure 4 is in a floating state. Because the capacitor 11 retains the voltage written during the light-emitting step, a specific gate-to-source voltage is applied to the thin film transistor 10, and the on-state is maintained. Therefore, as in the light-emitting step, a current flows through the organic EL element 12 in a forward direction, and this current flows through the thin film transistor 10 and flows into the wiring structure 4. Fig. 3 is a graph showing the time variation of the current 値 flowing through the thin film transistor 10 and flowing into the wiring structure 4 after the potential fluctuation step of each pixel circuit 1 is started. In the graph of Fig. 3, the current 値 flowing through the organic EL element 12 during the light emitting step is I. . As shown in FIG. 3, after the light-emitting step is completed and the potential change step is performed, a specific amount of current also flows through the organic EL element 12 and flows into the wiring structure 4. When the switch section 6 is turned off, the wiring structure 4 is brought into a floating state, and the potential V of the wiring structure 4 is gradually increased from the VDD at the time of the light emitting step due to the current flowing in. At this time, as shown in FIG. 1 and FIG. 2, the structure of the wiring structure 4 'because it is electrically connected to the thin film transistor 10 included in the plurality of pixel circuits 1 belonging to the same column' belongs to the same column. -14- 200428320 Multiple pixel circuit 1 supplies current to wiring structure 4. In fact, when the voltage between the gate and source of the thin film transistor 10 drops below the critical threshold voltage, a current flows into the wiring structure 4 and the potential of the wiring structure 4 continues to rise until this point. However, because the current 流入 will gradually decrease, when the potential of the wiring structure becomes-(1/2) VDD, the switch section 6 will be in the conducting state again, and the potential control section 5 will be used for potential control. . After the switch section 6 is turned on, the φ potential of the current passing through the organic EL element 12 and the thin-film transistor 10 and the wiring structure 4 according to the current supplied by the potential control section 5 is changed to a desired value. The above completes the potential change step. In the configuration of the image display device of this embodiment, when the potential of the electrically connected wiring structure 4 is changed to the source of the thin-film transistor 10 having a function of a driving element, the potential is flowed into the wiring structure through the organic EL element 12 4 The effect of the current. The advantages of this configuration will be described. As shown in the foregoing description, because the wiring structure 4 is electrically connected to the pixel circuits 1 belonging to the same column, the structure of the wiring structure 4 | extends upward in the display screen, so the physical length is extremely large. Therefore, other wiring structures such as the wiring structure 4 and the signal line 3 have to form a three-dimensional intersection, and a certain degree of parasitic capacitance is generated between these crossing wiring structures. In addition, the capacitor 11 is electrically connected to the capacitors 11 arranged in each pixel circuit 1, so that there is a capacitance caused by the capacitors 11. Because of the above points, the wiring structure 4 has a parasitic capacitance of about 5 000 pF. Therefore, due to the existence of the parasitic capacitance, a certain amount of charge needs to be supplied to the wiring structure 4 to change the potential. -15- 200428320 Therefore, for the purpose of potential fluctuation, only the potential control unit 5 supplies the electric charge to the wiring structure 4 in the configuration, which not only takes a long time, but also increases the burden on the potential control unit 5 due to the charge supply. There is a problem that the potential control section 5 generates heat. On the other hand, in this embodiment, a part of the electric charges supplied for the purpose of potential fluctuation is supplied by the electric current passing through the organic EL element 12, so the amount of electric charges supplied by the electric potential control section 5 can be reduced. Specifically, for example, when 50% of the necessary charge is supplied by a current through the thin film transistor 10, the power consumption of the potential control section 5 during the potential fluctuation step can be reduced by 50%, and the heat generation is also smaller than Conventional reduction of 50%. Fig. 4 is a graph of the calculation results of the time variation of the potential of the wiring structure 4 caused by the current flowing through the thin film transistor 10 during the potential fluctuation step under the same conditions as in Fig. 3. As shown in Fig. 4, at the beginning of the potential fluctuation step, the potential of the wiring structure 4 rises rapidly, and it rises to about 50% within 0.1 ms after the potential fluctuation step starts. In the potential fluctuation step, when the potential of the wiring structure 4 used is, for example, OV, 50% of the necessary charge can be supplied in 0.1 ms. In addition, the potential variation can be implemented in a short time by using a current passing through the thin film transistor 10, and there is an advantage that a reduction in the quality of a displayed image can be suppressed. That is, since the current flowing into the wiring structure 4 only flows through the organic EL element 12, the organic EL element 12 emits light at a specific brightness while the current flows into the wiring structure 4. On the other hand, when an image display device using an organic EL element 12 is used, especially in order to improve the visibility during animation display, it is preferable to perform black display in a specific period during displaying different images. Specifically, for example, an organic EL element 12 is caused to emit light at a desired brightness for a period of 8 ms equivalent to a half of the time allowed by the frame (approximately 16 ms). 16-200428320 Display, the rest During the period of 8 ms, it is preferable to stop the light emission of the organic EL element 12 and display the display in black. Therefore, if the light-emitting time of the organic EL element 12 is longer than the potential-changing step performed in the light-emitting step, it means that the black display time is reduced, so the image quality is lowered. In contrast, in this embodiment, the light-emitting time of the organic EL element 12 during the potential fluctuation step is stopped in a short time of about 0.1ms in the example in FIG. 4, so the display time for black is substantially The influence is negligible, and high-quality image display characteristics can be maintained. Also, as shown in FIG. 3, during the potential fluctuation step, the current 电 flowing through the thin film transistor 10, that is, the current 流 flowing through the organic EL element 12 and the light-emitting step are not completely the same, but will follow The passage of time decreases. Therefore, the brightness of the organic EL element 12 during the potential fluctuation step is different from that during the light emission step. When the light is emitted for a long time, a different image from the image to be displayed is displayed on the screen. However, the image display device of this embodiment is as shown in Fig. 4. Since the light emitting time of the organic EL element 12 during the potential change step can be suppressed to about 0 · lms, the user can hardly recognize the light emitting state. Therefore, when the image display device of this embodiment is used, it is also possible to suppress the degradation of the image quality from this viewpoint. In addition, the structure of the image display device of this embodiment is advantageous in that a current source is supplied to the wiring structure 4 through the organic EL element 12 at the time of the potential change step, so that there is no need to separately add a current source or the like. That is, at the end of the light-emitting step, the voltage of the write capacitor Π is maintained at substantially the same level as the light-emitting step, and a forward voltage is applied to the organic EL element 12. Therefore, when entering the potential change step, it is the same as the light step shown in Fig. 3, and the light step is the same as that shown in Fig. 3 ', maintaining the current flowing between the source and the drain of the thin film transistor 10. Therefore, in the "potential fluctuation step", a conventional circuit can be used as it is without using a special circuit for the purpose of supplying a current to the wiring structure 4 through the thin film transistor 10. In the image display device of this embodiment, the potential of the wiring structure 4 is not controlled only by the current flowing into the wiring structure 4 through the thin-film transistor 10, but the switching section is made again after entering a potential fluctuation step and after a specific time has passed. 6 is in a conducting state, and the potential of the wiring structure 4 is controlled by the potential control unit 5. Therefore, the advantages of using the function of the potential control section 5 when the potential of the wiring structure 4 fluctuates will be described below. As described above, the magnitude of the current flowing into the wiring structure 4 through the thin film transistor 10 is determined by the voltage between the gate and the source of the thin film transistor 10. At this time, since the source of the thin film transistor 10 and one of the electrodes of the capacitor 11 are electrically connected to the wiring structure 4, the voltage between the gate and the source of the thin film transistor 10 will increase as the potential of the wiring structure 4 rises. As the voltage decreases, the current flowing through the source and drain will decrease. Therefore, if the potential variation of the wiring structure 4 is performed only with the current passing through the thin film transistor 10, the wiring structure 4 may not be able to reach the desired potential due to the decrease in current 値, or it may take a long time to reach the desired potential. problem. In addition, since the system of the voltage between the gate and source of the thin film transistor 10 is determined according to the brightness of the organic EL element 12 during the light-emitting step, each frame of each pixel circuit 1 will be different, even if it is the same pixel. The circuit's frames will also be different. Therefore, the current flowing into the wiring structure 4 at the beginning of the potential fluctuation step of each specific pixel circuit or each frame will be different, and the potential fluctuation 値 of the wiring structure 4 depending on the flowing current will also be different. Therefore, it is difficult to change the potential of the wiring structure 4 to the desired one only through the current through the thin -18- 200428320 1! I ϊ film transistor 10, so it must be set separately to adjust the current through the film transistor 10値 Differences and other devices for the purpose. Therefore, in the structure of the image display device of this embodiment, the potential control unit 5 is retained, and the potential change using the current flowing through the organic EL element 12 and the potential change using the potential control unit 5 are performed at the same time. With the two structures, it is possible to compensate the difference in current flowing through the organic EL element 12 and the like, and implement the potential variation of the wiring structure 4. In addition, although the image display device of this embodiment retains the potential control section 5, as described above, it can reduce the driving load and reduce the heat generation compared to φ conventional. The foregoing has described the video display device of the present invention using the embodiments. However, the present invention is not limited by the embodiments. As long as it is for the industry, various embodiments and modifications can be associated with the embodiments according to the embodiments. For example, the structure of the pixel circuit constituting the image display device is not limited to that shown in FIG. 1, for example, the anode of the organic EL element 12 may be connected to a thin film as shown in FIG. 5 of the application example. Source of transistor 10. The arrangement position of the wiring structure 4 is not limited to the downstream position of the pixel circuit 1 depending on the direction of current flow, and the structure may be arranged, for example, upstream of the pixel circuit 1. In the embodiment, an organic EL element is used as an example of the current light-emitting element. However, an inorganic EL element or the like may be used. In addition, the current light-emitting element is not necessarily electrically equivalent to the light-emitting diode, and in terms of structure, it can emit light when current flows in either of the forward and reverse directions. When this type of current light-emitting element is used, the current not only flows into the wiring structure 4 through the thin film transistor 10, but also flows from the wiring structure 4 to the thin film transistor 10 side. -19- 200428320 has the potential to increase the range of potential variation. advantage. In addition, in the structure of the switch section 6 of the embodiment, the wiring structure 4 and the potential control section 5 are insulated from each other. However, in the structure, the resistance 値 between them may be changed. Even if it is not completely insulated, it is only necessary to make it difficult for current to flow from the wiring structure 4 to the potential control section 5. The wiring structure 4 can accumulate a specific ratio of charge, and the accumulation of this charge can change the potential of the wiring structure 4. As shown in the above description, according to this invention, in the structure, the potential fluctuation assisting device is used to compensate the potential fluctuation of the wiring structure, which can reduce the burden of the potential control device when changing the potential of the wiring structure φ, so it has a reduced potential control device Power consumption and heat generated by the potential control device. In addition, according to this invention, in the configuration, when the potential of the wiring structure is changed, the current passing through the current light-emitting element is used, and therefore there is an effect that it is not necessary to provide a new driving circuit or the like to perform the potential change. ㈤ [Brief description of the drawings] FIG. 1 is a schematic diagram of a configuration of an image display device according to an embodiment. Fig. 2 (a) is a light emitting step of the operation pattern diagram of the image display device of the embodiment, and Fig. 2 (b) is a potential fluctuation step. Fig. 3 is a graph showing the time variation of the current 流入 flowing into the wiring structure through the organic EL element. Fig. 4 is a graph showing the time change of the potential of the wiring structure. FIG. 5 is a circuit diagram of a conventional image display device. [Explanation of component symbols] 1 ... pixel circuit 2 ... scanning line-20-200428320 3 ... signal 4 ... wiring 5 ... potential 6, 13 ... 7 scan 8 ... signal 9, 10 ... 1 1 ... electricity 3 12… Yes 1 0 1… Letter 1 0 2… Thin 103… Electric 1 〇4… Thin 105… Yes 1 0 6… Scan 107… Electric 1 0 8… Wiring step control part switch part line drive circuit line drive circuit film Transistor I EL element number line film transistor container film transistor EL element trace current source line structure